shouldn't generate any namespace message if the endpoint name is empty

and add rpmsg_create_anon_ept to simplify the anonymous endpoint creation.
with the new API, the user should:
1.call rpmsg_create_ept for the main named service endpoint
2.call rpmsg_create_anon_ept for the aided service endpoint

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

lib/include/openamp/rpmsg.h

@@ -288,7 +288,7 @@ static inline void rpmsg_init_ept(struct rpmsg_endpoint *ept,
 				  rpmsg_ept_cb cb,
 				  rpmsg_ns_unbind_cb ns_unbind_cb)
 {
-	strncpy(ept->name, name, sizeof(ept->name));
+	strncpy(ept->name, name ? name : "", sizeof(ept->name));
 	ept->addr = src;
 	ept->dest_addr = dest;
 	ept->cb = cb;
@@ -325,6 +325,31 @@ int rpmsg_create_ept(struct rpmsg_endpoint *ept, struct rpmsg_device *rdev,
 		     const char *name, uint32_t src, uint32_t dest,
 		     rpmsg_ept_cb cb, rpmsg_ns_unbind_cb ns_unbind_cb);
 
+
+/**
+ * rpmsg_create_anon_ept - like rpmsg_create_ept but without name
+ *
+ * Create a RPMsg endpoint, initialize it with source address,
+ * remoteproc address and endpoint callback, and register it to
+ * the RPMsg device.
+ *
+ * @ept: pointer to rpmsg endpoint
+ * @src: local address of the endpoint
+ * @dest: target address of the endpoint
+ * @cb: endpoint callback
+ *
+ * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
+ * it binds an rpmsg address with an rx callback handler.
+ */
+
+static inline int rpmsg_create_anon_ept(struct rpmsg_endpoint *ept,
+					struct rpmsg_device *rdev,
+					uint32_t src, uint32_t dest,
+					rpmsg_ept_cb cb)
+{
+	return rpmsg_create_ept(ept, rdev, NULL, src, dest, cb, NULL);
+}
+
 /**
  * rpmsg_destroy_ept - destroy rpmsg endpoint and unregister it from rpmsg
  *                     device

lib/rpmsg/rpmsg.c

@@ -227,7 +227,7 @@ int rpmsg_create_ept(struct rpmsg_endpoint *ept, struct rpmsg_device *rdev,
 	rpmsg_init_ept(ept, name, addr, dest, cb, unbind_cb);
 	rpmsg_register_endpoint(rdev, ept);
 
-	if (rdev->support_ns && ept->dest_addr == RPMSG_ADDR_ANY) {
+	if (ept->name[0] && rdev->support_ns && ept->dest_addr == RPMSG_ADDR_ANY) {
 		/* Send NS announcement to remote processor */
 		metal_mutex_release(&rdev->lock);
 		status = rpmsg_send_ns_message(ept, RPMSG_NS_CREATE);
@@ -257,7 +257,7 @@ void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
 		return;
 
 	rdev = ept->rdev;
-	if (rdev->support_ns && ept->addr != RPMSG_NS_EPT_ADDR)
+	if (ept->name[0] && rdev->support_ns && ept->addr != RPMSG_NS_EPT_ADDR)
 		(void)rpmsg_send_ns_message(ept, RPMSG_NS_DESTROY);
 	metal_mutex_acquire(&rdev->lock);
 	rpmsg_unregister_endpoint(ept);